Multi-point supported five cylinder plunger pump

ABSTRACT

The present invention discloses a multi-point supported five cylinder plunger pump, including a power end assembly, a hydraulic end assembly and a reduction gearbox assembly, the power end assembly includes a crankcase, a crosshead case and a spacer frame, the crankcase, the crosshead case and the spacer frame are connected in sequence, the hydraulic end assembly is fixed on the spacer frame, the reduction gearbox assembly is fixed on the crankcase, a crankshaft support is disposed at the bottom of the crankcase, and the crankshaft support is used to support the crankcase, a crosshead support is disposed at the bottom of the crosshead case, and the crosshead support is used to support the crosshead case, a hydraulic support is disposed at the bottom of the spacer frame, and the hydraulic support is used to support the hydraulic end assembly. Beneficial effects: the multi-point support design of the crankcase, the crosshead case and the hydraulic end assembly can enhance the support strength of the plunger pump and reduce the vibration, thus better ensuring high load operation and more smoothly running.

TECHNICAL FIELD

The present invention relates to the technical field of plunger pumps, and specifically to a multi-point supported five cylinder plunger pump.

BACKGROUND

With the further development of unconventional oil and gas, shale oil and gas, the pressure and displacement requirements of fracturing operations are increasing, not only the operating pressure increases with the increase of horizontal well depth, but also the displacement required by a single well is higher and higher, as a result, the scale of fracturing operation becomes larger and larger, and the harsh operating conditions also put forward higher requirements for fracturing equipment, especially for the plunger pump. At present, in the development process of shale oil and gas, the operating pressure generally reaches 80-90 MPa or even higher, and the single-stage operating displacement is also generally 1800 m³-2000 m³ or even higher. Therefore, the plunger pump should not only be able to meet the continuous operation of high pressure and large displacement, but also ensure the quality stability under continuous high load operation, reduce the pump stop time and maintenance time. The most widely used fracturing truck on the market today is the 2500 fracturing truck equipped with a plunger pump of 2800 hp, other commonly used fracturing pumps include a 2500 hp pump, a 3300 hp pump, a 4000 hp pump and the like. Take the 2800 hp pump for example, due to power limitation, the single pump displacement is lower in high pressure operation. For a shale gas wellsite with a single-stage displacement requirement of 14-16 m³/min, near 20 fracturing trucks are totally needed to operate simultaneously to meet the total displacement requirements of fracturing operations. This will take up a large area of the wellsite, and increase the difficulty of equipment arrangement in narrow oil and gas field wellsite. Moreover, under increasingly harsh operating conditions, the frequency of problems on conventional plunger pumps is also increasing under high load operations for long time, increasing the maintenance and repair cost. In recent years, electric drive fracturing operations have emerged in which electric motors are used to solve the problem of constraints on diesel engine power, which are more suitable for driving high-power plunger pumps.

With the increase of plunger pump power, higher requirements are put forward for the operation stability and support strength of the plunger pump itself.

SUMMARY

To overcome the deficiencies in the prior art, an objective of the present invention is to provide a multi-point supported five cylinder plunger pump, the multi-point support design of a crankcase, a crosshead case and a hydraulic end assembly can enhance the support strength of the plunger pump and reduce the vibration, thus better ensuring high load operation and more smoothly running. In the power end assembly of the five cylinder plunger pump, the crankcase and the crosshead case are integrally welded so that the power end assembly has a higher structural strength and a better support stability, thus reducing the vibration of the whole pump. The cylinder spacing of the five cylinder plunger pump is designed to be 13-14 inches to increase the bearing areas of the connecting rod, the crosshead and the bearing bush, thus ensuring the high power output of the five cylinder plunger pump, specifically the power of the five cylinder plunger pump can be up to 7000 hp. The high-power five cylinder plunger pump can effectively solve the problems of narrow shale gas fracturing wellsite area and requirement for multiple fracturing equipment, and reduce the use of equipment so as to facilitate the wellsite arrangement.

The objective of the present invention is achieved by the following technical measures: a multi-point supported five cylinder plunger pump, including a power end assembly, a hydraulic end assembly and a reduction gearbox assembly, wherein the power end assembly includes a crankcase, a crosshead case and a spacer frame, the crankcase, the crosshead case and the spacer frame are connected in sequence, the hydraulic end assembly is fixed on the spacer frame, the reduction gearbox assembly is fixed on the crankcase, a crankshaft support is disposed at the bottom of the crankcase, and the crankshaft support is used to support the crankcase, a crosshead support is disposed at the bottom of the crosshead case, and the crosshead support is used to support the crosshead case, a hydraulic support is disposed at the bottom of the spacer frame, and the hydraulic support is used to support the hydraulic end assembly.

Further, the crankcase and the crosshead case are integrally welded to constitute a power end housing which is connected to the spacer frame, the power end housing includes a vertical plate, a bearing seat, a front end plate, a back cover plate, a base plate, a support plate and an upper cover plate; there are six vertical plates and six bearing seats, each vertical plate is connected to a corresponding bearing seat, and the six vertical plates are arranged in parallel to constitute a power end chamber; the base plate is mounted at the bottom of the power end chamber, the upper cover plate is mounted on the top of the power end chamber, the front end plate is mounted at the front end of the power end chamber, the back cover plate is mounted at the back end of the power end chamber, and the support plate is disposed between two adjacent vertical plates arranged in parallel.

Further, a crosshead assembly is provided within the crosshead case, a connecting rod assembly is provided between the crankcase and the crosshead case, and a crankshaft is provided within the crankcase, one end of the connecting rod assembly is connected to the crankshaft through a connecting rod bearing bush, the other end of the connecting rod assembly is connected to the crosshead assembly through a crosshead bearing bush, the connecting rod bearing bush and the crosshead bearing bush are both alloy coated steel backing bearing bushes.

Further, the cylinder spacing of the five cylinder plunger pump is 13-14 inches.

Compared with the prior art, the present invention has the following beneficial effects: the multi-point support design of a crankcase, a crosshead case and a hydraulic end assembly can enhance the support strength of the five cylinder plunger pump and reduce the vibration, thus better ensuring high load operation and more smoothly running. In the power end assembly of a five cylinder plunger pump, the crankcase and the crosshead case are integrally welded so that the power end assembly has a higher structural strength and a better support stability, thus reducing the vibration of the whole pump. The cylinder spacing of the five cylinder plunger pump is designed to be 13-14 inches to increase the bearing areas of the connecting rod, the crosshead and the bearing bush, thus ensuring the high power output of the five cylinder plunger pump, specifically the power of the five cylinder plunger pump can be up to 7000 hp. The high-power five cylinder plunger pump can effectively solve the problems of narrow shale gas fracturing wellsite area and requirement for multiple fracturing equipment, and reduce the use of equipment so as to facilitate the wellsite arrangement.

The present invention will be described in detail below with reference to the accompanying drawings and specific implementations.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a schematic structural diagram of a five cylinder plunger pump of the invention.

FIG. 2 is a schematic structural diagram of a power end assembly.

FIG. 3 is a schematic structural diagram of a power end housing.

FIG. 4 is a schematic structural diagram of a reduction gearbox assembly.

FIG. 5 is a sectional view of a planetary reduction gearbox.

FIG. 6 is a sectional view of a parallel reduction gearbox.

FIG. 7 is a schematic structural diagram of a crankshaft.

FIG. 8 is a schematic structural diagram of the connection between the connecting rod assembly and the crosshead assembly.

Wherein, 1. power end assembly, 2. reduction gearbox assembly, 3. hydraulic end assembly, 4. driving flange, 5. power end housing, 6. crankshaft, 7. bearing, 8. connecting rod bearing bush, 9. connecting rod body, 10. slide rail, 11. crosshead, 12. crosshead bearing bush, 13. pull rod, 14. spacer frame, 15. long screw, 16. nut, 17. clamp, 18. plunger, 19. valve housing, 20. crankshaft support, 21. crosshead support, 22. hydraulic support, 23. back cover plate, 24. vertical plate, 25. bearing seat, 26. base plate, 27. support plate, 28. front end plate, 29. upper cover plate, 30. parallel reduction gearbox, 31. planetary reduction gearbox, 32. internal gear, 33. planetary gear, 34. sun gear, 35. planetary carrier, 36. bull gear, 37. pinion, 38. spline, 39. connecting rod cap, 40. connecting rod bolt, 41. crosshead gland, 42. guide plate, 43. screw.

DESCRIPTION OF THE EMBODIMENTS

As shown in FIGS. 1 to 8, a five cylinder plunger pump with an integral power end structure, including a power end assembly 1, a hydraulic end assembly 3 and a reduction gearbox assembly 2, wherein one end of the power end assembly 1 is connected to the hydraulic end assembly 3, and the other end of the the power end assembly 1 is connected to the reduction gearbox assembly 2; the power end assembly 1 includes a crankcase, a crosshead case and a spacer frame 14, the crankcase and the crosshead case are integrally welded to constitute a power end housing 5 which is connected to the spacer frame 14, the power end housing 5 includes a vertical plate 24, a bearing seat 25, a front end plate 28, a back cover plate 23, a base plate 26, a support plate 27 and an upper cover plate 29; there are six vertical plates 24 and six bearing seats 25, each vertical plate 24 is connected to a corresponding bearing seat 25, and the six vertical plates 24 are arranged in parallel to constitute a power end chamber; the base plate 26 is mounted at the bottom of the power end chamber, the upper cover plate 29 is mounted on the top of the power end chamber, the front end plate 28 is mounted at the front end of the power end chamber, the back cover plate 23 is mounted at the back end of the power end chamber, and the support plate 27 is disposed between two adjacent vertical plates 24 arranged in parallel. In the power end assembly 1 of the five cylinder plunger pump, the crankcase and the crosshead case are integrally welded so that the power end assembly 1 has a higher structural strength and a better support stability, thus effectively decreasing the bearing deformation of the power end housing 5, reducing the vibration of the whole pump, and improving the running stability of the five cylinder plunger pump.

A crankshaft support 20 is disposed at the bottom of the crankcase, and the crankshaft support 20 is used to support the crankcase. A crosshead support 21 is disposed at the bottom of the crosshead case, and the crosshead support 21 is used to support the crosshead case. A hydraulic support 22 is disposed at the bottom of the spacer frame 14, and the hydraulic support 22 is used to support the hydraulic end assembly 3. The five cylinder plunger pump adopts a multi-point support design to enhance the support strength of the five cylinder plunger pump and reduce the vibration, thus better ensuring high load operation and more smoothly running.

The crankcase is provided with a crankshaft 6 and a bearing 7. The crankshaft 6 is integrally forged from alloy steel and includes six axle journals and five bellcranks, and one bellcrank is disposed between every two adjacent axle journals. The cylinder spacing of the five cylinder plunger pump is 13-14 inches. A design of increased cylinder spacing is beneficial to increase the contact areas between the crankshaft 6 and the connecting rod bearing bush 8, the crosshead 11 and the slide rail 10, and enhance the support strength, thus ensuring the high power output of the five cylinder plunger pump. The high-power five cylinder plunger pump can effectively solve the problems of narrow shale gas fracturing wellsite area and requirement for multiple fracturing equipment, and reduce the use of equipment so as to facilitate the wellsite arrangement. There are six bearings 7 mounted on the six axle journals, meanwhile the outer rings of bearings 7 are mounted on the six bearing seats 25 in the power end housing 5 so as to rotationally move within the bearing seats 25.

A spline 38 is provided within the crankshaft 6. The reduction gearbox assembly 2 is connected to the power end housing 5 through bolts and provided with an external spline which is connected to the spline 38 for power output. The installation angle of the reduction gearbox assembly 2 can be adjusted according to input requirements. A driving flange 4 is provided outside the reduction gearbox assembly 2, through which the power source is connected for power input.

A crosshead assembly is provided within the crosshead case, a connecting rod assembly is provided between the crankcase and the crosshead case, and a crankshaft 6 is provided within the crankcase. One end of the connecting rod assembly is connected to the crankshaft 6 through a connecting rod bearing bush 8, the other end of the connecting rod assembly is connected to the crosshead assembly through a crosshead bearing bush 12 allowing for reciprocating oscillation, and the other end of the crosshead assembly is connected to the pull rod 13. The pull rod 13 has a hollow structure. The connecting rod bearing bush 8 and the crosshead bearing bush 12 are both alloy coated steel backing bearing bushes, with a large width-diameter ratio and a high support strength.

There are two slide rails 10 fixed on the support plate 27 within the power end housing 5, the two slide rails 10 form a semi-circular space, in which a crosshead 11 is mounted for reciprocating linear motion.

The crosshead assembly is designed as a split structure, including a crosshead gland 41 and a crosshead 11, which are connected to each other to facilitate assembly with and disassembly from the connecting rod assembly.

The connecting rod assembly includes a connecting rod cap 39 and a connecting rod body 9, which are formed by integral forging and then cuffed, with high strength. The connecting rod cap 39 and the connecting rod body 9 are connected to each other through bolts, specifically, one end of the connecting rod body 9 is connected to the bellcrank through the connecting rod cap 39, the connecting rod bolt 40 and the connecting rod bearing bush 8, and the other end of the connecting rod body 9 is connected to the crosshead 11 through the crosshead gland 41 and the crosshead bearing bush 12. Two guide plates 42 are respectively fixed at the upper and the lower ends of the crosshead 11 through screws 43. The guide plates 42 are made of copper alloy, they contact with the slide rails 10 directly and move relative to each other.

The crankshaft 6, the connecting rod body 9, and the crosshead 11 are all provided with a lubricating oil circuit for lubrication of the bearing 7, the connecting rod bearing bush 8, and the crosshead bearing bush 12.

The hydraulic end assembly 3 includes a valve housing 19, a plunger 18, and a clamp 17 and so on. The hydraulic end assembly 3 connects the plunger 18 to the pull rod 13 through the clamp 17, and fixes them on the spacer frame 14 with a long screw 15 and a nut 16, and the long screw 15 is threaded to the power end housing 5.

The stroke of the five cylinder plunger pump with an integral power end structure is 11 inches. The design of long stroke is very suitable for the current demands for shale gas fracturing chain operation, decreasing the number of equipment in the wellsite, and improving operational efficiency and economy.

The reduction gearbox assembly 2 includes a planetary reduction gearbox 31 and a parallel reduction gearbox 30. One end of the planetary reduction gearbox 31 is connected to the power end assembly 1, the other end of the planetary reduction gearbox 31 is connected to the parallel reduction gearbox 30. The planetary reduction gearbox 31 and the parallel reduction gearbox 30 help to achieve two-stage reduction of the reduction gearbox assembly 2, with a reduction ratio of 8:1-15:1. The parallel reduction gearbox 30 includes a bull gear 36 and a pinion 37, which is used for primary reduction; the planetary reduction gearbox 31 includes an internal gear 32, four planetary gears 33, a sun gear 34, and a planetary carrier 35 to constitute a planetary gear mechanism, which is used for secondary reduction. The sun gear 34 is located at the center of the planetary gear mechanism, engaged with the planetary gear 33, and coaxial with the bull gear 36 of the parallel reduction gearbox 30. In running, an external power source is connected through a driving flange 4 to drive the input shaft to rotate, and the rotation is transferred to the bull gear 36 through the pinion 37 to achieve primary reduction, then transferred to the sun gear 34 through the bull gear 36, and then transferred to the planetary gear 33 through the sun gear 34 to drive the planetary carrier 35 to achieve secondary reduction, and finally the power is transferred to the crankshaft 6 through the spline 38. A large transmission ratio can be obtained by the two-stage transmission, effectively decreasing the input torque and reducing the number of strokes of the pump.

Operating principle: An external power or rotating speed is transferred through the driving flange 4 to drive the reduction gearbox assembly 2 to rotate. Power and torque are transferred to the crankshaft 6 by the spline 38 through two-stage transmission. The crankshaft 6 and the bearing 7 rotate within the power end housing 5, driving the motion of the connecting rod body 9, the crosshead 11 and the pull rod 13, and converting the rotational motion of the crankshaft 6 into the reciprocating linear motion of the pull rod 13. The pull rod 13 drives the plunger 18 through the clamp 17 to move back and forth within the valve case 19, thus realizing the low pressure liquid suction and high pressure liquid discharge, i.e, realizing the pumping of liquid.

It will be appreciated to persons skilled in the art that the present invention is not limited to the foregoing embodiments, which together with the context described in the specification are only used to illustrate the principle of the present invention. Various changes and improvements may be made to the present invention without departing from the spirit and scope of the present invention. All these changes and improvements shall fall within the protection scope of the present invention. The protection scope of the present invention is defined by the appended claims and equivalents thereof. 

1. A multi-point supported quintuplex plunger pump, including a power end assembly, a hydraulic end assembly and a reduction gearbox assembly; the power end assembly comprises a crankcase, a crosshead case and a spacer frame; the crankcase, the crosshead case and the spacer frame are connected in sequence; the hydraulic end assembly is fixed on the spacer frame; the reduction gearbox assembly is fixed on the crankcase; a crankshaft support is disposed at the bottom of the crankcase, and the crankshaft support is used to support the crankcase; a crosshead support is disposed at the bottom of the crosshead case, and the crosshead support is used to support the crosshead case; a hydraulic support is disposed at the bottom of the spacer frame, and the hydraulic support is used to support the hydraulic end assembly, wherein cylinder spacing of the quintuplex plunger pump is 13-14 inches, and there are two slide rails fixed on the support plate within the power end housing, the two slide rails form a semi-circular space, in which a crosshead is mounted for reciprocating linear motion.
 2. The multi-point supported quintuplex plunger pump according to claim 1, wherein the crankcase and the crosshead case are integrally welded to constitute a power end housing which is connected to the spacer frame; the power end housing comprises six vertical plates, six bearing seats, a front end plate, a back cover plate, a base plate, a support plate and an upper cover plate; each vertical plate is connected to a corresponding bearing seat, and the six vertical plates are arranged in parallel to constitute a power end chamber; the base plate is mounted at the bottom of the power end chamber, the upper cover plate is mounted on the top of the power end chamber; the front end plate is mounted at the front end of the power end chamber; the back cover plate is mounted at the back end of the power end chamber, and the support plate is disposed between two adjacent vertical plates arranged in parallel.
 3. The multi-point supported quintuplex plunger pump according to claim 1, wherein a crosshead assembly is provided within the crosshead case, a connecting rod assembly is provided between the crankcase and the crosshead case, and a crankshaft is provided within the crankcase; one end of the connecting rod assembly is connected to the crankshaft through a connecting rod bearing bush, and the other end of the connecting rod assembly is connected to the crosshead assembly through a crosshead bearing bush; the connecting rod bearing bush and the crosshead bearing bush are both alloy coated steel backing bearing bushes.
 4. (canceled)
 5. (canceled) 